Arrangement for orienting rockets moving in liquids

ABSTRACT

The horizontal orientation of a rocket moving in a liquid is achieved by an arrangement in which a magnet is attached to the rocket body. The axis of the rocket and the magnetic axis of the magnet form an azimuthal angle α, which determines the direction of the rocket relative to the geomagnetic meridian.

The present invention relates to an arrangement for achieving horizontalorientation of a rocket moving in a liquid.

Rockets which are operated in liquids, e.g. water, are used, forexample, for transporting explosives to solid materials to becomminuted, an example being the explosive fragmentation of coal in aliquid-filled seam in the course of being mined. For this purpose, therocket carrying the explosive passes to the seam through a borehole fromthe surface. After reaching the seam level, the rocket is in generalautomatically orientated, as a result of adjusting its center ofgravity, at the intended angle of elevation, which predominantlycorresponds to the horizontal or to directions deviating only slightlytherefrom. In contrast, the azimuthal angle remains undetermined, sothat after the propellant charge has been ignited the rocket will movein an arbitrary horizontal direction. However, it is usually desirableto mine the coal in a very particular direction, for example onedetermined by the geological conditions.

It is an object of the present invention to provide an arrangement bymeans of which the direction of motion of a rocket moving in a liquidcan also be adjusted in respect of its azimuthal orientation.

I have found that this object is achieved when a magnet is attached tothe rocket body, and the axis of the rocket and the magnetic axis of themagnet form an azimuthal angle α, which determines the direction of therocket relative to the geomagnetic meridian.

Further details and advantages of the novel arrangement are to be foundin the Example described below with reference to the drawing.

In the drawing:

FIG. 1 shows a schematic representation of a rocket body with a barmagnet

FIG. 2 shows a spherical representation of the orientation

FIG. 3 shows a schematic representation of a shift in the center ofgravity of the rocket body by means of the bar magnet.

The novel arrangement for achieving horizontal azimuthal orientation isshown schematically in FIG. 1. The arrangement comprises the rocket body1 to be moved and a bar magnet 2 which is attached to 1 eitherexternally or internally, by screws or pins, or other suitable means ofattachment, so that the rocket axis 3 and the axis 4 of the bar magnet 2form an azimuthal angle α, which determines the direction of the rocketrelative to the geomagnetic meridian 5 (FIG. 2).

The aligning force K is defined by the torque acting at the center ofgravity of the rocket body, according to the mathematical relationship

    K·a=H.M. sin α,

where a is the lever arm, H is the strength of the earth's magneticfield, M is the magnetic moment of the bar magnet 2, and α is theazimuthal angle.

The magnetic field of the earth is relatively weak. By suitable choiceof the magnetic moment of the bar magnet it is, however, possible toattain the required directional force K. The applied force K serves toovercome the forces of inertia corresponding to the moment of inertia##EQU1## of the rocket to be orientated, where α is the angularacceleration, as well as to overcome the frictional forces which are inany case noticeable in a liquid. The available permanent magnets, suchas barium ferrites and aluminum/nickel/cobalt alloy bar magnets, whichpossess remanence flux densities which are high enough readily toovercome both the forces of inertia and the frictional forces. In onerespect, the frictional forces even prove useful, in that they assistthe oscillation into the final position by strongly damping the rotarymotion.

The bar magnet 2 can be attached to the rocket as additional ballast, asillustrated, for example, in FIG. 3. By displacing the center of gravitySp of the rocket, it is also possible simultaneously to adjust the angleof elevation β of the rocket direction. By this combination of measures,virtually any point P on a sphere of reference around the center ofgravity of the rocket may be reached (FIG. 2).

The Example which follows illustrates the mode of action of the novelarrangement.

EXAMPLE

A rocket of 20 cm length and 3.5 cm diameter carries a propellant chargeof 25 g of pellet powder and, in addition, an auxiliary charge of 250 gof explosive. To stablize the course, a guide sleeve of 10 cm length and5 cm diameter is pushed coaxially over the end of the rocket body sothat the end of the sleeve projects 5 cm beyond the jet opening. A barmagnet having a weight of 50 g and a magnetic moment of 5.10⁻⁷ V.s.m isattached underneath the rocket and has its magnetic north/south axis at45° to the rocket axis, so that, after orientation, the rocket pointsapproximately north-west. Simultaneously with the attachment of themagnet, a compensation in respect of weight is also effected such that,first, the rocket axis is horizontal and, secondly, the rocketapproximately achieves a floating state in the supporting liquid. Thecomplete rocket arrangement is introduced in an arbitrary orientationinto a concentrated CaCl₂ solution which has a density of 1.4 g/cm³ andis under a pressure of 150 bar. After about 2 seconds, the rocketoscillates into the intended direction and points at the target. Thepropellant charge is then ignited by a pressure igniter with a 5 seconddelay. Thereafter, the rocket moves on a stable course to the target,where the explosive charge is ignited by a percussion detonator.

I claim:
 1. An improved rocket device for carrying an explosive chargeto a liquid filled coal seam including a body having an axis andcontaining a propellant charge and an explosive charge, said improvementcomprising:a permanent magnet secured to the said rocket body at anazimuthal angle to said rocket body axis said magnet having a magneticmoment great than 5.10⁻⁷ volts second meter sufficient with respect tothe weight of said rocket to orient the said rocket body at acorresponding angle to the north-south magnetic meridian when said bodyis suspended in said liquid, and said magnet being manually movablelengthwise of the rocket device so as to be positioned on said body inthe direction of said axis to displace the center of gravity of the saidrocket and magnet to adjust an angle of elevation of said rocket bodyaxis in said liquid.
 2. An arrangement as claimed in claim 1, whereinthe magnet is a bar magnet.